The presence of misfolded protein, such as ALS‐linked variants of SOD1, in stress granules (SGs) leads to a gradual loss of dynamics, suggesting that SG loss‐of‐function could be a factor in aggregation‐linked disease.

Synopsis

The presence of misfolded protein in stress granules alters their dynamic state and induces a phase transition. This process is counteracted by chaperones and autophagy, acting as a stress granule quality control system.

Misfolded proteins have a tendency to aggregate in stress granules (SGs).

Misfolded proteins promote a conversion of SGs into an aberrant solid‐like state.

This is an open access article under the terms of the Creative Commons Attribution 4.0 License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

This is an open access article under the terms of the Creative Commons Attribution 4.0 License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

One of the most fundamental processes of life is protein synthesis by the ribosome. Although much is known about the function and structure of this macromolecular complex, our understanding on its assembly is still vague. In this issue of The EMBO Journal, Malyutin et al (2017) provide a detailed picture of one of the latest assembly stages of the yeast 60S ribosomal subunit. The cryo‐EM map of the 60S‐Nmd3‐Lsg1‐Tif6 complex sheds new light on the function of Nmd3, Lsg1 and Tif6—and their release mechanisms—right before the 60S subunit joins the pool of actively translating ribosomes.

New high‐resolution cryo‐EM structures capture the final stages of 60S subunit maturation, illustrating the ordered remodeling and assembly factor release steps required for the formation of a functional ribosome.

Synopsis

Small GTPase ROP2 is a new component of the auxin‐responsive TOR signaling pathway, in which ROP2 activated by auxin promotes TOR activation and up‐regulation of translation of mRNAs that harbor uORFs within their leaders.

Small GTPase ROP2 interacts with TOR in Arabidopsis.

TOR is phosphorylated and activated in response to auxin via GTP‐bound ROP2.

ROP2 promotes TOR accumulation on endosome‐like structures.

GTP‐bound ROP2 promotes both polysome loading and translation reinitiation of mRNAs that harbor uORFs within their leaders in a TOR‐responsive manner.

Folding of proteins entering the secretory pathway in mammalian cells necessitates disulfide bond formation in the ER. This study shows that cytosolic thioredoxin reductase 1 and NADPH are required to reduce non‐native disulfides in such proteins.

Synopsis

Correcting non‐native disulfides in secreted proteins, an unexpected role for the cytosol.

Formation of the correct disulfides in proteins entering the secretory pathway requires a pathway for disulfide reduction.

NADPH formation in the cytosol drives disulfide reduction in the endoplasmic reticulum.

The cytosolic thioredoxin reductase pathway is required for correct folding of proteins with complex disulfides.

An unknown mechanism exists to transfer reducing equivalents across the membrane of the endoplasmic reticulum.

This is an open access article under the terms of the Creative Commons Attribution 4.0 License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.